Bell was using the Opera LED Face Mask, which gave her face a creepy glow in the dark room.

The face mask is fairly popular with several celebrities, and claims to improve skin elasticity and kill bacteria.

Celebs are willing to do some pretty out there things to maintain their image. Kim Kardashian West, for instance, famous for once airing her vampire facial, recently revealed that she even has a hair clause in her will to make sure her mane always looks good. Kristen Bell, on the other hand, managed to scare her husband of four plus years, Dax Shepard, with her nighttime skincare routine when he came to bed, only to find what he called "an electronic monster in his bed."

After exiting the bathroom, Shepard was surprised to find Bell, 37, suddenly all aglow in their bed. "I came out of the bathroom tonight and found this electric monster in my bed," he jokingly captioned a video of his discovery.

Filming his illuminated partner in repose, he laughs while asking, "Will you please tell me [that] this is real?"

"This is real!" the "Frozen 2" star proclaims while sitting up to give us a full glimpse at her glowing face.

"This is not a bit to scare the s--- out of me, right?" Shepard confirms as the two burst into laughter.

Real, it was: The mask in question appears to be the Opera LED Face Mask (roughly $2,757 in USD), a "low-level light therapy LED facial mask" which uses three different wavelengths to do everything from produce collagen and improve skin elasticity (therefore reducing age signs and wrinkles), to killing bacteria (thereby reducing acne).